Autoimmune cytopenias are a significant complication observed after hematopoietic cell transplant (HCT) and carries a substantial rate of morbidity and mortality. This entity is usually challenging to treat, resulting in prolonged hospitalization and predisposes patients to complications either directly due to the specific cytopenia or due to the immune suppression that is part of its therapeutic management. One of the mediators of refractory autoimmune cytopenias are antibodies produced by plasma cells, which are historically challenging to target. The purpose of this study is to use a proteasome inhibitor called Bortezomib for the treatment of refractory autoimmune cytopenias after HCT, and monitor the clinical response.